1. Field of the Invention
The present invention relates to a spindle motor, a rotor assembly used in the spindle motor, and a player including the spindle motor.
2. Description of the Related Art
As shown in FIGS. 34 and 35, in a player for a disk and the like, a spindle motor 301 is attached to be erected on the upper surface side of a chassis 303 by a screw 304 or the like by placing a stator substrate 302 serving as a motor support plate on the upper surface of the chassis 303. The spindle motor 301 includes a tubular bearing section 305 provided in the stator substrate 302, a bearing 306 attached to the inner periphery of the bearing section 305, a wiring board 307 attached on the stator substrate 302, an iron-core coil 308 attached to the outer periphery of the tubular bearing section 305, a rotating shaft 309 attached to the bearing 306, and a rotor assembly 310 attached to the tip of the rotating shaft 309.
The rotor assembly 310 includes a rotor 311 made of metal and a disk table 312 of synthetic resin outsert-molded in the rotor 311. A rotor magnet 313 forming a pair with the iron-core coil 308 is attached to the inner peripheral surface of the rotor 311. A chucking magnet 314 that magnetically chucks a hub of a disk-like recording medium is attached to the upper surface of the disk table 312. A centering spring 315 is arranged at the outer periphery of the magnet 314.
As shown in FIG. 36 in which the rotor 311 and the disk table 312 are separated, the rotor 311 has a substantially circular top surface section 311a and a tubular skirt section 311b. The disk table 312 is outsert-molded with the tubular skirt section 311b arranged at a predetermined space 311c from the outer periphery of the top surface section 311a. On the other hand, the disk table 312 includes a table main body section 312a located on the outer surface side of the rotor 311 and a rotor-inner-surface superimposing section 312b that is located on the inner surface side of the rotor 311 and integrally combine the table main body section 312a with the rotor 311. When the disk table 312 is resin-molded, the rotor-inner-surface superimposing section 312b is formed by extending a part of the resin to the inner surface side of the rotor 311 through the space 311c between the top surface section 311a and the tubular skirt section 311b (see, for example, JP-A-2005-322318).